Combustors used in gas turbine engines, such as aircraft engines, conventionally include sheet metal combustion liners and sheet metal combustion dome assemblies. The combustion liners include coannular outer and inner combustion liners joined at their upstream ends by an annular dome for defining therein an annular combustion dome. The dome includes a plurality of circumferentially spaced carburetors for providing a fuel/air mixture into the combustor which is conventionally ignited for generating combustion gases. The combustor is supplied with compressed airflow from the compressor upstream thereof which subjects the dome to a pressure loading by the high velocity compressed airflow. In addition, the combustor structure is vibrationally active and subject to thermal expansion of the components during engine operation resulting in relative movement between the various components.
It is well known that during ground operation or during take-off at some airports, the engines exert a powerful suction effect in front of them, resulting in some instances in the ingestion of birds or other objects.
The combustor domes in present operation, when subjected to birdstrike to the engine core, have occasionally shown disengagement of the fuel nozzle from the swirler. The movement of the swirler, relative to the fuel nozzle, is due to the large bellmouth of the secondary swirler which supports the primary swirler but acts as a moment arm during impact. Such moment arm produces a moment about the center of the swirler, causing the swirler to rotate. The dome spectacle plate is then distorted allowing disengagement of the fuel nozzle.